4 fresh green chillies, with seeds, cut lengthways into sixths
250g/9oz fresh or frozen coconut flesh, blitzed in a food processor or grated
handful chopped coriander, to finish
1 onion, thinly sliced
250ml/9fl oz coconut milk
2 tbsp black mustard seeds
1 tsp salt
1 tsp ground turmeric
4–6 tbsp vegetable oil
350g/12oz peeled raw prawns